Add extension with rule based routing sampler

Author: jack-berg

javaagent/Dockerfile

@@ -2,5 +2,6 @@ FROM eclipse-temurin:11-jre
 
 ADD build/libs/app.jar /app.jar
 ADD build/agent/opentelemetry-javaagent.jar /opentelemetry-javaagent.jar
+ADD build/agent/opentelemetry-javaagent-extension.jar /opentelemetry-javaagent-extension.jar
 
-ENTRYPOINT java -jar -javaagent:/opentelemetry-javaagent.jar /app.jar
+ENTRYPOINT java -jar -javaagent:/opentelemetry-javaagent.jar -Dotel.javaagent.extensions=/opentelemetry-javaagent-extension.jar /app.jar

javaagent/README.md

@@ -47,12 +47,15 @@ Watch for spans, metrics, and logs in the collector log output
 
 ## File Configuration
 
-By default, this example uses the [environment variable configuration schema](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/configuration/sdk-environment-variables.md) to configure the SDK. However, it also includes [sdk-config.yaml](./sdk-config.yaml) which demonstrates how the file configuration scheme can be used instead. `sdk-config.yaml` demonstrates view configuration to disable a metric, something which is not available in the environment variable configuration scheme.
+By default, this example uses the [environment variable configuration schema](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/configuration/sdk-environment-variables.md) to configure the SDK. However, it also includes [sdk-migration-config.yaml](./sdk-migration-config.yaml) which demonstrates how the file configuration scheme can be used instead. `sdk-migration-config.yaml` extends the [opentelemetry-configuration sdk-migration-config.yaml](https://github.com/open-telemetry/opentelemetry-configuration/blob/v0.3.0/examples/sdk-migration-config.yaml) template, demonstrating:
+
+- Configuration of instrumentation (see `.instrumentation.java`) 
+- Configuration of [rule based routing sampler](https://github.com/open-telemetry/opentelemetry-java-contrib/tree/main/samplers) (see `.tracer_provider.sampler`)
 
 To use file configuration instead of the environment variable scheme, add the following before starting the application and collector:
 
 ```shell
 export OTEL_EXPERIMENTAL_CONFIG_FILE=/sdk-migration-config.yaml
 ```
 
-Note that toggling file configuration causes the environment variable configuration scheme to be ignored completely. However, there is support for environment variable substitution within configuration files.
+Note besides the environment variables referenced in `sdk-migration-config.yaml` using [substitution syntax](https://opentelemetry.io/docs/specs/otel/configuration/data-model/#environment-variable-substitution), environment variables are ignored.

javaagent/build.gradle.kts

@@ -16,15 +16,18 @@ java {
 }
 
 val agent = configurations.create("agent")
+val extension = configurations.create("extension")
 
 dependencies {
     implementation(platform(SpringBootPlugin.BOM_COORDINATES))
     implementation("io.opentelemetry:opentelemetry-api")
 
     //spring modules
     implementation("org.springframework.boot:spring-boot-starter-web")
+    implementation("org.springframework.boot:spring-boot-starter-actuator")
 
     agent("io.opentelemetry.javaagent:opentelemetry-javaagent:2.9.0")
+    extension("io.opentelemetry.contrib:opentelemetry-samplers:1.40.0-alpha")
 }
 
 val copyAgent = tasks.register<Copy>("copyAgent") {
@@ -33,9 +36,19 @@ val copyAgent = tasks.register<Copy>("copyAgent") {
     rename("opentelemetry-javaagent-.*\\.jar", "opentelemetry-javaagent.jar")
 }
 
+val copyExtension = tasks.register<Copy>("copyExtension") {
+    from(extension.files) {
+        include("opentelemetry-samplers-*.jar")
+        exclude("*sources.jar")
+        exclude("*javadoc.jar")
+    }
+    into(layout.buildDirectory.dir("agent"))
+    rename(".*\\.jar", "opentelemetry-javaagent-extension.jar")
+}
 
 tasks.named<BootJar>("bootJar") {
     dependsOn(copyAgent)
+    dependsOn(copyExtension)
 
     archiveFileName = "app.jar"
 }

javaagent/sdk-migration-config.yaml

@@ -13,7 +13,7 @@
 # NOTE: With the exception of env var substitution syntax, SDKs ignore environment variables
 # when interpreting config files. For example, if "disabled: ${OTEL_SDK_DISABLED:-false}"
 # is replaced with "disabled: false", then setting the env var OTEL_SDK_DISABLED will have
-# no effect. See https://opentelemetry.io/docs/specs/otel/configuration/file-configuration/
+# no effect. See https://opentelemetry.io/docs/specs/otel/configuration/data-model/#file-based-configuration-model
 # for more information. The following spec defined env vars are NOT referenced and are thus
 # ignored:
 #
@@ -143,6 +143,22 @@ tracer_provider:
       local_parent_not_sampled:
         # Configure sampler to be always_off.
         always_off: {}
+      # Uncomment to configure the rule_based_routing sampler from https://github.com/open-telemetry/opentelemetry-java-contrib/tree/main/samplers
+      # to drop spans to spring actuator endpoints.
+      # Configure the parent_based sampler's root sampler to be rule_based_routing sampler.
+      # root:
+      #  rule_based_routing:
+      #    # Fallback to the always_on sampler if the criteria is not met.
+      #    fallback_sampler:
+      #      always_on:
+      #    # Only apply to SERVER spans.
+      #    span_kind: SERVER
+      #    rules:
+      #      # Drop spans where url.path matches the regex /actuator.* (i.e. spring boot actuator endpoints).
+      #      - action: DROP
+      #        attribute: url.path
+      #        pattern: /actuator.*
+
 
 # Configure meter provider.
 meter_provider:
@@ -256,8 +272,11 @@ instrumentation:
   java:
     common:
       default-enabled: ${OTEL_INSTRUMENTATION_COMMON_DEFAULT_ENABLED:-true}
+    # Configuration logback-appender instrumentation. Properties adapted from:
+    # https://github.com/open-telemetry/opentelemetry-java-instrumentation/tree/main/instrumentation/java-util-logging/javaagent
     java-util-logging:
       enabled: ${OTEL_INSTRUMENTATION_JAVA_UTIL_LOGGING_ENABLED:-true}
+      experimental-log-attributes: ${OTEL_INSTRUMENTATION_LOGBACK_APPENDER_EXPERIMENTAL_LOG_ATTRIBUTES:-false}
     # Configuration logback-appender instrumentation. Properties adapted from:
     # https://github.com/open-telemetry/opentelemetry-java-instrumentation/tree/main/instrumentation/logback/logback-appender-1.0/javaagent
     logback-appender: